Tracking platform system

• US 5,526,433 A
• Filed: 05/12/1995
• Issued: 06/11/1996
• Est. Priority Date: 05/03/1993
• Status: Expired due to Term

• Current Assignee: 2236008 Ontario Inc. (Blackberry Limited)
• Original Assignee: University of British Columbia
• Inventors: Zakarauskas, Pierre, Cynader, Max S.
• Primary Examiner(s): Isen, Forester W.
• Application Number:
  US08/440,425
• Time in Patent Office: 396 Days
• Field of Search: 381/110, 381/92, 381/122, 367/104, 367/120
• US Class Current: 381/92
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers
• CPC Class Codes: H04R 25/405 by combining a plurality of transducers
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/027 Spatial or constructional arrangements of microphones, e.g. in dummy heads

Abstract

A self-steering platform system incorporates at least three and preferably four microphones circumferentially spaced about the platform which is mounted for movement preferably around two mutually perpendicular axes. A sound source is selected and separate audio signals from the microphones are analyzed by a control which based on differences between the signals from the microphones emanating from the selected source determines the location of the selected source. The orientation of the platform is then adjusted by the control relative to the selected sound source. The present invention is particularly useful for mounting a shotgun or parabolic microphone to enhance sound from a selected source.

Claims

1. A signal processing system for identifying different localized sound sources for aiming a self steering system comprising a plurality of microphone means arranged in spaced relationship relative to each other, each of said microphone means receiving input signals from each of said different localized sound sources and generating its respective audio signal based on said input signals it received from all of said localized sources, means for processing said audio signals from each said microphone said means for processing including means to identify a selected sound source from said different sound sources, means to determine an envelope for each of said audio signals, rectifier means for producing a rectified signal, low pass filter means for filtering said rectified signal to provide a filtered signal and means for non-linearly processing said envelopes including means to decimate said filtered signal at local maxima and to define discrete narrow peaks representative of input signals received from each said localized source, means to determine a time delay between said peaks defined in at least two of said audio signals and representative of a selected one of said localized sources, control means to aim said system and means for operating said control means based on said time delay.

2. A signal processing system as defined in claim 1 wherein said plurality of microphone means comprise four said microphone means arranged in two pairs with microphone means of a first pair of said two pairs being mounted in spaced relationship along a first axis and microphone means of a second pair of said two pairs mounted in spaced relationship on a second axis substantially perpendicular to said first axis.